Dr. Richard Massey (Bill Pullman) and Sister Jo (Natascha McElhone) travel to Prague to speak with a noted expert on Satanism, who leads them to a secret library hidden in a crypt. Within the crypt, Massey and Sister Jo find a strange box that contains a puzzle that may unlock clues about the birth of the Anti-Christ. Back at the Sisters of Mercy convent, the sisters and comatose Olivia find themselves under attack by followers of Satanist Isaiah Haden (Michael Massee). Meanwhile, Haden attempts to escape from prison, and Hawk (Mark Rendall) is being brainwashed by his captors.